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3D Imaging of Porous Media Using Laser Scanning Confocal Microscopy with Application to Microscale Transport Processes (open access)

3D Imaging of Porous Media Using Laser Scanning Confocal Microscopy with Application to Microscale Transport Processes

We present advances in the application of laser scanning confocal microscopy (LSCM) to image, reconstruct, and characterize statistically the microgeometry of porous geologic and engineering materials. We discuss technical and practical aspects of this imaging technique, including both its advantages and limitations. Confocal imaging can be used to optically section a material, with sub-micron resolution possible in the lateral and axial planes. The resultant volumetric image data, consisting of fluorescence intensities for typically {approximately}50 million voxels in XYZ space, can be used to reconstruct the three-dimensional structure of the two-phase medium. We present several examples of this application, including studying pore geometry in sandstone, characterizing brittle failure processes in low-porosity rock deformed under triaxial loading conditions in the laboratory, and analyzing the microstructure of porous ceramic insulations. We then describe approaches to extract statistical microgeometric descriptions from volumetric image data, and present results derived from confocal volumetric data sets. Finally, we develop the use of confocal image data to automatically generate a three-dimensional mesh for numerical pore-scale flow simulations.
Date: February 10, 1999
Creator: Fredrich, J.T.
Object Type: Article
System: The UNT Digital Library
Airport Financing: Annual Funding As Much As $3 Billion Less Than Planned Development (open access)

Airport Financing: Annual Funding As Much As $3 Billion Less Than Planned Development

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed airport funding issues, focusing on: (1) the amount airports are spending on capital development and the sources of those funds; (2) comparing airports' plans for development with current funding levels; and (3) what effect will various proposals to increase or make better use of existing funding have on airports' ability to fulfill their capital development plans."
Date: February 10, 1999
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 99, No. 284, Ed. 1 Wednesday, February 10, 1999 (open access)

Altus Times (Altus, Okla.), Vol. 99, No. 284, Ed. 1 Wednesday, February 10, 1999

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: February 10, 1999
Creator: Cole, Carol
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Alvin Advertiser (Alvin, Tex.), Ed. 1 Wednesday, February 10, 1999 (open access)

The Alvin Advertiser (Alvin, Tex.), Ed. 1 Wednesday, February 10, 1999

Weekly newspaper from Alvin, Texas that includes local, state, and national news along with advertising.
Date: February 10, 1999
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Analyzing industrial furnace efficiency using comparative visualization in a virtual reality environment. (open access)

Analyzing industrial furnace efficiency using comparative visualization in a virtual reality environment.

We describe an interactive toolkit used to perform comparative analysis of two or more data sets arising from numerical simulations. Several techniques have been incorporated into this toolkit, including (1) successive visualization of individual data sets, (2) data comparison techniques such as computation and visualization of the differences between data sets, and (3) image comparison methods such as scalar field height profiles plotted in a common coordinate system. We describe each technique in detail and show example usage in an industrial application aimed at designing an efficient, low-NOX burner for industrial furnaces. Critical insights are obtained by interactively adjusted color maps, data culling, and data manipulation. New paradigms for scaling small values in the data comparison technique are described. The display device used for this application was the CAVE virtual reality theater, and we describe the user interface to the visualization toolkit and the benefits of immersive 3D visualization for comparative analysis.
Date: February 10, 1999
Creator: Freitag, L. & Urness, T.
Object Type: Article
System: The UNT Digital Library
Architectural Surety Applications for Building Response to Dynamic Loads (open access)

Architectural Surety Applications for Building Response to Dynamic Loads

This paper provides a summary introduction to the emerging area of Architectural Surety{trademark} applications for buildings and infrastructures that are subjected to dynamic loads from blast and naturally occurring events. This technology area has been under investigation to assist with the definition of risks associated with dynamic loads and to provide guidance for determining the required upgrading and retrofitting techniques suggested for reducing building and infrastructure vulnerabilities to such dynamic forces. This unique approach involves the application of risk management techniques for solving problems of the as-built environment through the application of security, safety, and reliability principles developed in the nuclear weapons programs of the United States Department of Energy (DOE) and through the protective structures programs of the German Ministry of Defense (MOD). The changing responsibilities of engineering design professionals are addressed in light of the increased public awareness of structural and facility systems' vulnerabilities to malevolent, normal, and abnormal environment conditions. Brief discussions are also presented on (1) the need to understand how dynamic pressures are affected by the structural failures they cause, (2) the need to determine cladding effects on columns, walls, and slabs, and (3) the need to establish effective standoff distance for perimeter barriers. A …
Date: February 10, 1999
Creator: Matalucci, R.V. & Mayrhofer, C.
Object Type: Article
System: The UNT Digital Library
Argonne National Laboratory - West's approach to filter characterization. (open access)

Argonne National Laboratory - West's approach to filter characterization.

Like other DOE facilities, ANL-W uses a variety of nuclear grade, industrial grade, or furnace-type particulate filters to control airborne radioactivity and hazardous contaminants in radiological containment structures or processes. As designed, these filters entrain and ultimately concentrate contaminants in the media. Toxic metal contaminants include cadmium, chromium, lead; and mercury present in sufficient concentrations to exhibit the hazardous waste characteristic of toxicity as defined in 40 CFR 261.24. Radionuclide contaminants deposited in the media may at times accumulate in sufficient quantity to classify the filter as transuranic or remote-handled waste. Upon their removal from the ventilation system, these particulate filters become wastes, which must be characterized to determine their hazardous and radioactive classifications. A well defined filter characterization process is essential for the proper/consistent waste characterization and minimization and for maintaining personnel radiological exposures as-low-as-reasonably-achievable (ALARA) (1,2). ANL-W has developed an approach to filter sampling and characterization to meet these needs. The ANL-W filter sampling and characterization process is designed to ensure representative sampling and/or process knowledge is utilized in characterizing the filters. The data obtained through sampling and/or process knowledge is used to show compliance with the Resource Conservation and Recovery Act (3) and Treatment/Storage/Disposal Facility Waste Acceptance …
Date: February 10, 1999
Creator: Miller, T. A.
Object Type: Article
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 77, No. 88, Ed. 1 Wednesday, February 10, 1999 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 77, No. 88, Ed. 1 Wednesday, February 10, 1999

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: February 10, 1999
Creator: Dobbs, Gary
Object Type: Newspaper
System: The Portal to Texas History
Calorimetric Studies of the Energetics of Order-Disorder in the System Mg(1-x)Fe(x)Ca(CO(3))(2) (open access)

Calorimetric Studies of the Energetics of Order-Disorder in the System Mg(1-x)Fe(x)Ca(CO(3))(2)

Calorimetric studies by Chai and Navrotsky (1996) on dolomite-ankerite energetic have been extended by including two additional types of samples: a very disordered stoichiometric MgCa(CO{sub 3}){sub 2} prepared from low temperature aqueous solution and three largely ordered natural samples of intermediate iron content. Combining these data with previous work, three distinct trends of energetic can be seen: those for samples with nearly complete order, nearly complete disorder, and intermediate order. From these trends, the enthalpy of complete disordering is estimated to be 33 {+-} 6 kJ/mol for MgCa(CO{sub 3}){sub 2} and 18 {+-} 5 kJ/mol for FeCa(CO{sub 3}){sub 2}.
Date: February 10, 1999
Creator: Brady, P.; Dooley, D.; Navrotsky, A. & Reeder, R.
Object Type: Article
System: The UNT Digital Library
Characterization Report on Sand, Slag, and Crucible Residues and on Fluoride Residues (open access)

Characterization Report on Sand, Slag, and Crucible Residues and on Fluoride Residues

This paper reports on the chemical characterization of the sand, slag, and crucible (SS and C) residues and the fluoride residues that may be shipped from the Rocky Flats Environmental Technology Site (RFETS) to Savannah River Site (SRS).
Date: February 10, 1999
Creator: Murray, A.M.
Object Type: Report
System: The UNT Digital Library
The Clifton Record (Clifton, Tex.), Vol. 104, No. 12, Ed. 1 Wednesday, February 10, 1999 (open access)

The Clifton Record (Clifton, Tex.), Vol. 104, No. 12, Ed. 1 Wednesday, February 10, 1999

Semi-weekly newspaper from Clifton, Texas that includes local, state, and national news along with advertising.
Date: February 10, 1999
Creator: Smith, W. Leon
Object Type: Newspaper
System: The Portal to Texas History
The Collegian (Hurst, Tex.), Vol. 11, No. 16, Ed. 1 Wednesday, February 10, 1999 (open access)

The Collegian (Hurst, Tex.), Vol. 11, No. 16, Ed. 1 Wednesday, February 10, 1999

Weekly student newspaper published in Hurst, Texas serving the Tarrant County Junior College District that includes school news and information along with advertising.
Date: February 10, 1999
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Colony Courier (The Colony, Tex.), Vol. 2, No. 14, Ed. 1 Wednesday, February 10, 1999 (open access)

The Colony Courier (The Colony, Tex.), Vol. 2, No. 14, Ed. 1 Wednesday, February 10, 1999

Weekly newspaper from The Colony, Texas that includes local, state, and national news along with advertising.
Date: February 10, 1999
Creator: Chiniewicz, Susan
Object Type: Newspaper
System: The Portal to Texas History
Comparing Evolutionary Programs and Evolutionary Pattern Search Algorithms: A Drug Docking Application (open access)

Comparing Evolutionary Programs and Evolutionary Pattern Search Algorithms: A Drug Docking Application

Evolutionary programs (EPs) and evolutionary pattern search algorithms (EPSAS) are two general classes of evolutionary methods for optimizing on continuous domains. The relative performance of these methods has been evaluated on standard global optimization test functions, and these results suggest that EPSAs more robustly converge to near-optimal solutions than EPs. In this paper we evaluate the relative performance of EPSAs and EPs on a real-world application: flexible ligand binding in the Autodock docking software. We compare the performance of these methods on a suite of docking test problems. Our results confirm that EPSAs and EPs have comparable performance, and they suggest that EPSAs may be more robust on larger, more complex problems.
Date: February 10, 1999
Creator: Hart, W.E.
Object Type: Article
System: The UNT Digital Library
CRAX/Cassandra Reliability Analysis Software (open access)

CRAX/Cassandra Reliability Analysis Software

Over the past few years Sandia National Laboratories has been moving toward an increased dependence on model- or physics-based analyses as a means to assess the impact of long-term storage on the nuclear weapons stockpile. These deterministic models have also been used to evaluate replacements for aging systems, often involving commercial off-the-shelf components (COTS). In addition, the models have been used to assess the performance of replacement components manufactured via unique, small-lot production runs. In either case, the limited amount of available test data dictates that the only logical course of action to characterize the reliability of these components is to specifically consider the uncertainties in material properties, operating environment etc. within the physics-based (deterministic) model. This not only provides the ability to statistically characterize the expected performance of the component or system, but also provides direction regarding the benefits of additional testing on specific components within the system. An effort was therefore initiated to evaluate the capabilities of existing probabilistic methods and, if required, to develop new analysis methods to support the inclusion of uncertainty in the classical design tools used by analysts and design engineers at Sandia. The primary result of this effort is the CMX (Cassandra Exoskeleton) …
Date: February 10, 1999
Creator: Robinson, D.
Object Type: Article
System: The UNT Digital Library
Cross-Sectional Scanning Tunneling Microscopy of InAsSb/InAsP Superlattices (open access)

Cross-Sectional Scanning Tunneling Microscopy of InAsSb/InAsP Superlattices

Cross-sectional scanning tunneling microscopy has been used to characterize compositional structure in InAs{sub 0.87}Sb{sub 0.13}/InAs{sub 0.73}P{sub 0.27} and InAs{sub 0.83}Sb{sub 0.17}/InAs{sub 0.60}P{sub 0.40} strained-layer superlattice structures grown by metal-organic chemical vapor deposition. High-resolution STM images of the (110) cross section reveal compositional features within both the InAs{sub x}Sb{sub 1{minus}x} and InAs{sub y}P{sub 1{minus}y} alloy layers oriented along the [{bar 1}12] and [1{bar 1}2] directions--the same as those in which features would be observed for CuPt-B type ordered alloys. Typically one variant dominates in a given area, although occasionally the coexistence of both variants is observed. Furthermore, such features in the alloy layers appear to be correlated across heterojunction interfaces in a manner that provides support for III-V alloy ordering models which suggest that compositional order can arise from strain-induced order near the surface of an epitaxially growing crystal. Finally, atomically resolved (1{bar 1}0) images obtained from the InAs{sub 0.87}Sb{sub 0.13}/InAs{sub 0.73}P{sub 0.27} sample reveal compositional features in the [112] and [{bar 1}{bar 1}2] directions, i.e., those in which features would be observed for CuPt-A type ordering.
Date: February 10, 1999
Creator: Allerman, A. A.; Biefeld, R. M.; Yu, E. T. & Zuo, S. L.
Object Type: Article
System: The UNT Digital Library
The Cuero Record (Cuero, Tex.), Vol. 105, No. 6, Ed. 1 Wednesday, February 10, 1999 (open access)

The Cuero Record (Cuero, Tex.), Vol. 105, No. 6, Ed. 1 Wednesday, February 10, 1999

Weekly newspaper from Cuero, Texas that includes local, state, and national news along with advertising.
Date: February 10, 1999
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Diffusion of Ca and Mg in Calcite (open access)

Diffusion of Ca and Mg in Calcite

The self-diffusion of Ca and the tracer diffusion of Mg in calcite have been experimentally measured using isotopic tracers of {sup 25}Mg and {sup 44}Ca. Natural single crystals of calcite were coated with a thermally-sputtered oxide thin film and then annealed in a CO{sub 2} gas at one atmosphere total pressure and temperatures from 550 to 800 C. Diffusion coefficient values were derived from the depth profiles obtained by ion microprobe analysis. The resultant activation energies for Mg tracer diffusion and Ca self-diffusion are respectively: E{sub a}(Mg) = 284 {+-} 74 kJ/mol and E{sub a}(Ca) = 271 {+-} 80 kJ/mol. For the temperature ranges in these experiments, the diffusion of Mg is faster than Ca. The results are generally consistent in magnitude with divalent cation diffusion rates obtained in previous studies and provide a means of interpreting the thermal histories of carbonate minerals, the mechanism of dolomitization, and other diffusion-controlled processes. The results indicate that cation diffusion in calcite is relatively slow and cations are the rate-limiting diffusing species for the deformation of calcite and carbonate rocks. Application of the calcite-dolomite geothermometer to metamorphic assemblages will be constrained by cation diffusion and cooling rates. The direct measurement of Mg tracer …
Date: February 10, 1999
Creator: Cygan, Randall T. & Fisler, Diana K.
Object Type: Article
System: The UNT Digital Library
[Email Exchange on Texas Case Study Schools] (open access)

[Email Exchange on Texas Case Study Schools]

A comprehensive email exchange capturing strategic insights and discussions on the Texas case study schools. Addressed to both the Steering Committee and Directors, this correspondence delves into key considerations, shared perspectives, and collaborative efforts related to the case study initiative.
Date: February 10, 1999, 3:42 p.m.
Creator: unknown
Object Type: Letter
System: The UNT Digital Library
[Email Exchange on Working with Greenbriar School] (open access)

[Email Exchange on Working with Greenbriar School]

A documented email conversation capturing strategic discussions and considerations related to collaborative efforts with Greenbriar School.
Date: February 10, 1999, 3:29 p.m.
Creator: unknown
Object Type: Letter
System: The UNT Digital Library
Evolutionary software for autonomous path planning (open access)

Evolutionary software for autonomous path planning

This research project demonstrated the effectiveness of using evolutionary software techniques in the development of path-planning algorithms and control programs for mobile vehicles in radioactive environments. The goal was to take maximum advantage of the programmer's intelligence by tasking the programmer with encoding the measures of success for a path-planning algorithm, rather than developing the path-planning algorithms themselves. Evolutionary software development techniques could then be used to develop algorithms most suitable to the particular environments of interest. The measures of path-planning success were encoded in the form of a fitness function for an evolutionary software development engine. The task for the evolutionary software development engine was to evaluate the performance of individual algorithms, select the best performers for the population based on the fitness function, and breed them to evolve the next generation of algorithms. The process continued for a set number of generations or until the algorithm converged to an optimal solution. The task environment was the navigation of a rover from an initial location to a goal, then to a processing point, in an environment containing physical and radioactive obstacles. Genetic algorithms were developed for a variety of environmental configurations. Algorithms were simple and non-robust strings of behaviors, …
Date: February 10, 1999
Creator: Couture, S. & Hage, M.
Object Type: Article
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Wednesday, February 10, 1999 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Wednesday, February 10, 1999

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: February 10, 1999
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
Final rapid reactivation project environmental assessment (open access)

Final rapid reactivation project environmental assessment

The US Department of Energy (DOE) has prepared an environmental assessment (EA) for the Rapid Reactivation Project at Sandia National Laboratories, New Mexico. The EA analyzes the potential effects of a proposal to increase production of neutron generators from the current capability of 600 units per year up to 2,000 units per year. The project would use existing buildings and infrastructure to the maximum extent possible to meet the additional production needs. The increased production levels would necessitate modifications and additions involving a total area of approximately 26,290 gross square feet at Sandia National Laboratories, New Mexico, Technical Area 1. Additional production equipment would be procured and installed. The no-action alternative would be to continue production activities at the current capability of 600 units per year. The EA analyzes effects on health, safety, and air quality, resulting from construction and operation and associated cumulative effects. A detailed description of the proposed action and its environmental consequences is presented in the EA.
Date: February 10, 1999
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Finance and supply management project execution plan (open access)

Finance and supply management project execution plan

As a subproject of the HANDI 2000 project, the Finance and Supply Management system is intended to serve FDH and Project Hanford major subcontractor with financial processes including general ledger, project costing, budgeting, and accounts payable, and supply management process including purchasing, inventory and contracts management. Currently these functions are performed with numerous legacy information systems and suboptimized processes.
Date: February 10, 1999
Creator: BENNION, S.I.
Object Type: Report
System: The UNT Digital Library